Gerry Kirk, president of Sand World International, travels the world building sand castles. In fact, his team is listed in the Guinness Book of World Records for a 64-foot (19-meter) structure built last year on Fiesta Island off San Diego.

In the United States, Kirk's pick for best castle-building beach is Seal Beach in Los Angeles.

Outside the United States, his pick is Cabo Pulmo, on the tip of Baja California, so named by native fishermen because it was once a center for sponge-diving, and "pulmo" refers to lung capacity.

Both locations offer the right kind of sand for building castles, Kirk says:

"(You need) something that will take compaction. You can pack it up and it'll hold its shape. That requires a good mix of grain size without getting too large a grain."

Color also is important for contrast when you are carving windows in your sand castle, he says. "If it's a lighter colored sand, you get a nice contrast. Seal Beach is dark sand but when it dries out it's light enough to make really good contrast."